How do I run a script every time a modem disconnects

[normap]

I would like to run a script file everytime a certain modem disconnects from our system which would update a database. How would I do this?

 

[wakeboarder]

We use a cron job on NCR UNIX that runs avery 2 minutes that will check to see if the modem is enabled and not in use. It will disable the modem and log the action. It does a little more logic like check to see if the modem was manually enabled and allow ten minutes for login before disabling the modem. It will also will check for valid users on the modem and kill unwanted usrers.